Supporting Information for. Remarkably high temperature spin transition exhibited by two new metal-organic frameworks

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1 Supporting Information for Remarkably high temperature spin transition exhibited by two new metal-organic frameworks Xin Bao, a Peng-Hu Guo, a Wei Liu, a Jiri Tucek, b Wei-Xiong Zhang, a Ji-Dong Leng, a Xiao-Ming Chen, a Il ya Gural skiy, c Lionel Salmon, c Azzedine Bousseksou c and Ming-Liang Tong* a a Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, State Key Laboratory of Optoelectronic Materials and Technologies, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou , P. R. China b Regional Centre of Advanced Technologies and Materials, Department of Experimental Physics, Faculty of Science, Palacky University, Slechtitelu 11, Olomouc, Czech Republic. c Laboratoire de Chimie de Coordination, UPR 8241 CNRS, 205 Route de Narbonne, Toulouse, France Corresponding author: tongml@mail.sysu.edu.cn Contents of the Supporting Information 1. Materials and General Procedures 2. PXRD Spectra 3. X-Ray Crystallography 4. Magnetic measurements 5. DSC measurements 6. Mössbauer measurements 7. Variable temperature Raman spectra measurements 8. Simulation of the two-step SCO behaviors of 1 and 2 Fig. S1. Variable PXRD patterns for 1 (above) and 2 (below). Fig. S2. TG curves for 1 (in black) and 2 (in red) under N 2 atmosphere. Fig. S3. PXRD patterns of 1 as-synthesized (green) and of 1 immerging in morpholine (blue), pyridine (red) and DMF (black) for one month. Fig. S4. Structural illustrations of 1. Fig. S5. Experimental PXRD (red continuous line) and Rietveld refined pattern (blue circles) and difference patterns (black line) for 2 at 600 K. Fig. S6. The experimental χ M T versus T curves of 1 and 2 in the temperature range K. Fig. S7. Mössbauer spectrum of 2 and tentative fitting results at 453 K. Fig. S8. Scheme of spin transition route for 1 and 2: both Fe1 and Fe2 in LS states at LS-LS phase; Fe1 in LS state and Fe2 in HS state at HS-LS phase; both Fe1 and Fe2 in HS states at HS-HS phase. Table S1. Mössbauer hyperfine parameters of 2. S1

2 1. Materials and General Procedures All of the chemicals were obtained from commercial sources and used without further purification. The IR spectra were recorded from KBr disc in the range cm 1 with a Bruker-tensor 27 spectrometer. 2. PXRD Spectra PXRD patterns of 1 and 2 were recorded on a D8 ADVANCE X-Ray Diffractometer (CuKa nm). The Rietveld refinement of the XRD pattern of 2 at 600 K was carried out using the program of Materials Studio. 3. X-Ray Crystallography Diffraction intensities of 1 and 2 were collected on a Bruker SMART Apex CCD diffractometer with graphite-monochromated Mo Kα radiation (λ = Å) or on a Rigaku R-AXIS SPIDER IP diffractometer (Mo Kα, λ = Å) at 293(2) and 383(2) K. The structures were solved by direct method, and all non-hydrogen atoms were refined anisotropically by least-squares on F 2 using the SHELXTL program. Hydrogen atoms on organic ligands were generated by the riding mode (G. M. Sheldrick, SHELXTL97, program for crystal structure refinement, University of Göttingen, Germany, 1997). Crystal data for 1 at 293(2) K: C 24 H 16 FeN 10, g mol -1, triclinic, P-1, a = (12) Å, b = (12) Å, c = (2) Å, α = (2), β = (2), γ = (2), V = (2) Å 3, Z = 2, ρ = g cm -3. R 1 /wr 2 = / (I > 2σ(I)). Crystal data for 1 at 383(2) K: a = 8.966(16) Å, b = 9.309(16) Å, c = 15.08(3) Å, α = 94.38(3), β = (4), γ = (5), V = 1132(4) Å 3, Z = 2, ρ = g cm -3. R 1 /wr 2 = / ( I > 2σ(I)). Crystal data for 2 at 293(2) K: C 26 H 20 FeN 10, g mol -1, triclinic, P-1, a = (3) Å, b = (4) Å, c = (7) Å, α = (1), β = (1), γ = (1), V = (8) Å 3, Z = 2, ρ = g cm -3. R 1 /wr 2 = / (I > 2σ(I)). Crystal data for 2 at 383(2) K: a = (9) Å, b = (11) Å, c = (19) Å, α = (4) o, β = (3), γ = (3), V = (2) Å 3, Z = 2, ρ = g cm -3. R 1 /wr 2 = / (I > 2σ(I)). Unit cell parameters for 2 at 600 K from the refinement of PXRD data: a = 9.561(4) Å, b = 9.786(4) Å, c = (6) Å, α = (3), β = (2), γ = (2), V = Å 3. R wp = 2.81%, R p = 1.59%. CCDC numbers: (1_293K), (1_383K), (2_293K), (2_383K) and (2_600K). S2

3 5. Magnetic measurements Magnetic measurements were performed using a Quantum Design MPMS XL-7 SQUID magnetometer. The susceptibility measurements for 1 and 2 were first performed in the K temperature range with an applied field of 2.0 koe. Samples were sealed in parafilm to avoid any orientation of the crystallites. Then an oven was installed to take measurements from K. Samples were wrapped in tinfoil. The magnetic data were corrected for the sample holder and diamagnetic contributions. 6. DSC measurements DSC measurements were carried out on polycrystalline samples of 1 and 2 using a Netzsch DSC 204 F1 Phoenix instrument under nitrogen at a scan rate of 5 K min -1 in both heating and cooling modes. 7. Mössbauer measurements Mössbauer experiments were carried out by using a 57 Co/Rh source in a constant-acceleration transmission spectrometer. The spectrometer was calibrated by using a standard α-fe foil. 8. Variable temperature Raman spectra measurements Variable-temperature Raman spectra of 2 were collected using a Laser Micro-Raman Spectrometer (Renishaw invia) with nm laser source. Samples were enclosed in nitrogen atmosphere on the heat plate of a THMS600 (Linkam) liquid-nitrogen cryostage. 9. Simulation of the two-step SCO behaviors of 1 and 2 Considering the large separation between the two sets of spin transition, inter-subset interaction was neglected here to simplify the simulation. Domain model 1,2 was applied to simulate each SCO process (equations 1-6), and the two-step behavior was well reproduced by the sum of those two processe s ln 1 HS 1 = 1 1 HS 1 R R (1) ln 1 HS 2 = 2 2 HS 2 R R ΔH 1 =2ΔH 1 (exp) (3) ΔH 2 =2ΔH 2 (exp) (4) ΔS 1 = 2ΔS 1 (exp) = 2ΔH 1 /T c1 (5) ΔS 2 = 2ΔS 2 (exp) = 2ΔH 2 /T c2 (6) where n stands for the number of molecules per domain; ΔH 1,2 (exp) and ΔS 1,2 (exp) are enthalpy and entropy variations deriving from DSC measurements; γ HS1 and γ HS2 are the spin fractions for each step and both taken to go from 0 to 1, and the total high spin fraction γ HS = (γ HS1 + γ HS2 )/2. 1. Sorai, M.; Seki, S. J. Phys. Chem. Solids, 1974, 35, 555. S3 (2)

4 2. Kahn, O. Molecular Magnetism, VCH, Weinheim, 1993, pp. 67. S4

5 Normalized Intensity 623K 573K 523K 473K 423K 373K 343K 293K 293K_simulated θ / degree Normalized Intensity 600K 550K 500K 450K 383K 293K θ / degree 293K_simulated Fig. S1. Variable PXRD patterns for 1 (above) and 2 (below). S5

6 Mass % T / K Fig. S2. TG curves for 1 (in black) and 2 (in red) under N 2 atmosphere. Normalized Intensity In DMF In Pyridine In Morpholine As synthesized θ / degree Fig. S3. PXRD patterns of 1 as-synthesized (in green) and of 1 immerging in morpholine (in blue), pyridine (in red) and DMF (in black) for one month. S6

7 Fig. S4. Structural illustrations of 1: Coordination environments of Fe1 and Fe2 (left); 2D (4,4) rhombic grids (middle); Crystal packing of two adjacent 2D layers highlighting the interlayer face-to-face π π interactions (red dotted lines) and edge-to-face π π interactions (orange dotted lines) (right). Hydrogen atoms have been omitted for clarity. Intensity / exp. cal. 75 difference 60 background peak position θ / degree Fig. S5. Experimental PXRD (red continuous line) and Rietveld refined pattern (blue circles) and difference patterns (black line) for 2 at 600 K. The ticks are the position of the Bragg reflections, and the bottom trace is the residual. R wp = 4.35%,R p = 2.62%,R comb = 4.47% S7

8 Fig. S6. The experimental χ M T versus T curves of 1 and 2 in the temperature range K. Fig. S8. Schematic of spin transition route for 1 and 2: both Fe1 and Fe2 in LS states at LS-LS phase; Fe1 in LS state and Fe2 in HS state at HS-LS phase; both Fe1 and Fe2 in HS states at HS-HS phase. Table. 1. Mössbauer hyperfine parameters of the 2, where δ is the isomer shift, ΔE Q is the quadrupole splitting, Γ is the linewidth and RA is the relative spectral area of individual spectral components. Temperature Component δ ± 0.01 ΔE Q ± 0.01 Γ ± 0.01 RA ± 1 Assignment (K) (mm/s) (mm/s) (mm/s) (%) 300 Doublet LS Fe 2+ Doublet LS Fe Doublet LS Fe 2+ Doublet HS Fe Doublet LS Fe 2+ Doublet HS Fe 2+ S8